Space is an obvious setting for science fiction.
The future is too, whether it be teched-out or dystopic (or sometimes both.) But the idea of a whole other world sitting beneath our feet and our notice is one that really intrigues me. I thought I was alone in this regard until I saw this list of "underground realms from science fiction" on io9 a while back. The choices for the list really run the gamut of arcane civilizations, technologically advanced empires, or "lots of dinosaurs."
It's rather axiomatic that Verne's Journey to the Center of the Earth be included on any list of this nature. Hard to dis the king in this regard. The io9 article pretty much focuses on the film adaptation of the book, highlighting the spectacle of giant mushrooms, the dinosaurs, and the connection to Atlantis.
I was glad to see 1956's The Mole People make an appearance. True, one could quibble as to whether or not it's really science fiction, but come on. It's got Alan Napier in it as a Sumerian priest named Ishtar. That's right. The guy who went on to play Alfred on the Adam West Batman series. Dragging things down towards the negative a bit is the fact that the actual "mole people" creatures aren't seen all that much in the movie and we're left instead with a small city full of albino Sumerians. Cheaper that way, I guess.
Comic books are replete with subterranean worlds. The list goes to the obvious example of Subterranea in Marvel Comics. Good choice, really. It truly is an expansive environment all its own where characters ranging from the Fantastic Four to the Hulk have had adventures. Another plus is that it is absolutely loaded with diverse races. There are the Lava Men, the Mole Men that are under the rule of...well, the Mole Man (who is apparently the villain d'jour in the Fantastic Four reboot), and Lizard Men. Note, said Lizard Men are not to be confused with the variety found in the Savage Land. Not sure what DC Comics has as their version aside from Skartaris in the Warlord series. I love Warlord but it's more of a fantasy comic (quibble quibble quibble).
My favorite entry on the list? Seatopia! That's right, Kaiju fans. The underground kingdom from Godzilla vs. Megalon makes an appearance. In this installment of the original line of Godzilla films, a race of "cryptoterrestrials" gets annoyed by our nuclear tests on the surface. They send the monster cockroach Megalon to give us the what for. Godzilla defeats this monster with the help of a robot named Jet Jaguar (if you've seen the movie, I just know you've got the Jet Jaguar song in your head right now.) Oh yeah, somehow the Seatopians are in contact with aliens from Nebula M.
The readers had a few good suggestions of their own. Beneath the Planet of the Apes had mutated and telepathic humans living beneath what was left of New York City. They also worshiped a nuclear missile, so that's a kitschy plus. I was also glad to see someone else remember The Inhumanoids. Oh and The Last Dinosaur! It's an unintentionally hilarious b-movie about an expedition that drills into the Earth to find a prehistoric world and....oh it's better that you just find out for yourself.
What would I add? Superman and the Mole Men comes to mind. The titular character fights yet more mole people from an underground civilization. I believe the 1951 short film was actually a precursor to the George Reeves series. Anyway, it's got the usual subterranean tropes: tiny, gnome-like people who are disturbed by humans and our incessant drilling for oil. They send an expedition to the surface with sophisticated (maybe not in depiction) technology, misunderstandings ensue, and the wacky hijinks just go on from there.
Along similar lines was an old movie serial called The Phantom Empire. Gene Autry plays a cowboy who discovers a malevolent civilization exists beneath his ranch. Cowboys versus underground dwellers. Yeah, I said it.
Speaking of wacky, if you want to read really great stuff about underground civilizations, check out The Shaver Mysteries. It's all about the Hollow Earth.
Best part about it? The author claims it's not science fiction.
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